package com.netty.demo.text.securechat;

import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.handler.ssl.SslHandler;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.GenericFutureListener;
import io.netty.util.concurrent.GlobalEventExecutor;

import java.net.InetAddress;

public class SecureChatServerHandler extends ChannelHandlerAdapter {

    static final ChannelGroup channels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        // Once session is secured, send a greeting and register the channel to the global channel
        // list so the channel received the messages from others.
        ctx.pipeline().get(SslHandler.class).handshakeFuture().addListener(new GenericFutureListener<Future<? super Channel>>() {
            @Override
            public void operationComplete(Future<? super Channel> future) throws Exception {
                ctx.writeAndFlush("Welcome to " + InetAddress.getLocalHost().getHostName() + " secure chat service!\n");
                ctx.writeAndFlush("Your session is protected by " +ctx.pipeline().get(SslHandler.class).engine().getSession()
                        .getCipherSuite()+" cipher suite.\n");
                channels.add(ctx.channel());
            }
        });
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        String message = (String)msg;
        for (Channel c:channels){
            if(c != ctx.channel()){
                c.writeAndFlush("[" + ctx.channel().remoteAddress() + "] " + msg + '\n');
            }else {
                c.writeAndFlush("[you] " + message + '\n');
            }
        }
        // Close the connection if the client has sent 'bye'.
        if("bye".equalsIgnoreCase(message.toLowerCase())){
            ctx.close();
        }
    }
}
